Secondary electric clock.



N0. 63'],I79. Patented Nov. l4, I899. J. J. STOCKALL, SR. SECONDARYELECTRIC CLOCK.

(Application filed Sept. 12, 189Q 3 Sheets8heet; I.

(No Model.)

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No. 637,|79. Patented No I4 I899 J. J. STOCKALL, Sn.

SECONDARY ELECTRIC CLOCK.

(Application filed Sept. 12, 1899.) (No Model.) t 3 Sheets Sheet 3.

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UNITED STATES PATENT OFFICE.

JAMES JOHN STOOKALL, SE, OF LONDON, ENGLAND.

SECONDARY'ELECTRIC CLOCK.

SPECIFICATION forming part of Letters Patent No. 637,179, dated November14, 189 Application filed $cptember 12, 1899. Serial No. 780,267. (Nomodel.)

To ctZZ whom it may concern.-

Be it known that I, JAMns Joan STOOKALL, Sn, a citizen of England,residing at 6 and 8 Olerkenwell road, London, England, have invented acertain new and useful improved apparatus for effecting a step-by-steprotary motion applicable for electric-clock and other machineryrequiring accurate control of motion, (for which I have made applicationfor patent in Great Britain, No. 1,394, dated January 20, 1899,) ofwhich the following is a specification.

My invention relates to apparatus worked by a step-by-step rotary orratchet motion which requires to be accurately controlled, so that atevery forward motion of a wheel this shall only be capable of beingturned through a definite angle, its motion being then arrested andeifectually locked in the position into which it has been moved untilthe commencement of the next forward impulse. For this purpose I employthe following mechanism: An arm to which a to-and-fro motion is impartedby any suitable means, such as by an el'ectromagnet and spring orweight, has connected to it two pallets adapted to engage on oppositesides of the toothed wheel which is to receive the step-by-step motion.The arm is so connected to these pallets that as it moves in thedirection for rotating the wheel it first causes the one pallet tobecome disengaged from the teeth of the wheel with a radially-slidingmotion and at the same time causes the other pallet to engage with theteeth of the wheel on the opposite side with a radially-sliding motion,afterwhich this pallet, by a turning motion, is made to effect therotation of the wheel through a certain distance, which is limited by afixed stop against which the pallet strikes. On the return mo tion ofthe arm the last-named pallet is moved out of engagement with the wheeland the first-named pallet is at the same time moved into engagement, sothat the wheel is effectually locked in position until theabove-described action is repeated.

On the accompanying drawings are shown Various arrangements for carryingout my said invention.

Figures 1 and 2 show, respectively, an ele vation and horizontal sectionof one arrange ment. Fig. 3 shows a part elevation of a sec ondarrangement; Figs. 4 and 5, respectively, an elevation and sectionalplan of another modification; and Fig. 6 shows a part elevation of amodification in which the pallet-actuating arm is supported above theratchetwheel instead of below it.

In the arrangement shown at Figs. 1 and 2, a is the toothed wheel towhich a step-by-step rotary motion is to be imparted. In front of thisis arranged a horizontal bar I), which at the left-hand end worksbetween fixed guidepins 0 0, so arranged that the bar can slide throughthem without any vertical play, while the right-hand end works betweentwo other guide-pins (Z d at a certain distance apart, so that the barhas a certain amount of vertical play. The bar I) has a pin 6 projectingthrough a slotted hole in an arm f, pivoted to the casing g at h andreceiving a to-andfro motion by any suitable means, such as by beingattracted at intervals in one direction by an electromagnet and thenmoved back again by a spring or weight. On each end of the bar I) arepallet-pins i and j, in such positions relatively to the toothed wheelthat when the bar is brought into the position shown in full lines bythe backward motion of the armfthe pin '5 is engaged between the teethof wheel a, and consequently effectually prevents any rotation of thelatter, while the pinj is just free of the teeth of the wheel. On thecommencement of the forward motion of arm f pin j first comes intoengagement with the teeth of wheel a and pin t' then moves out ofengagement therewith, whereupon on the further motion of the armfand barI) an incline 7c on the end of the latter in bearing against thelowerguide-pin cl causes the bar to rise at that end until it comes incontact with the upper pin 01. By such rising motion of the bar itspallet-pin jis made to carry the wheel around with it the exact distancedetermined by the stop-pin d. On the arm f and bar I) now commencing tomove backward the pin 1' again enters into engagement with the teeth ofwheel a before pin j has been brought out of engagement therewith, andconsequently the wheel a is again effectually locked in the positioninto which it has been moved.

It will be seen that in order to allow of the above-described action ofthe two pallets upon the wheel the teeth of the latter require to bemade of considerably greater depth than is necessary for ratchetpurposes, as shown, so as to allow of the required extent of motion ofthe pallets while in engagement with the teeth.

The pawl Z, pivoted to the framing engaging with the teeth of the wheela, is provided, so as to prevent any possible backward motion thereofduring the very short interval before the pin i engages with the teethon the commencement of the backward motion of the bar 1). On thecompletion of such backward motion the right-hand end of the bar againdrops into its original position ready for the repetition of theabove-described action.

Fig. 3 shows a modification of the above arrangement, in which the bar bis replaced by two separate bars m and a, pivoted separately to the armf. The action is otherwise precisely the same as above described.

In the modification shown in elevation and sectional plan at Figs. l and5 the rotary motion of the wheel a is not effected by an incline on thepallet j, as before, but by a pawl o, actuated by the upper end of thearmf. The pallets t' andj are here formed as plates instead of pins, thepallet 2' operating in pr cisely the same manner as before, while thepallet j only serves to accurately limit the motion of the wheel ct incoming against the stop d while in engagement with the teeth. The pawl ois pivoted to a radial arm p, mounted loose on the axis of the wheel aand having a tail carrying two pins q q, between which the end of thelever f has a certain amount of play. The object of this is that the armfniust first move a sufficient distance forward for bringing the pallett' out of engagement, and the pallet j into engagement, with the teethof the wheel before it moves the arm 13 and pawl 0 forward for turningthe wheel through the required distance.

An additional locking of the wheel Ct is effected after it has beenturned by a lockingpawl 1", having a spring-tail s situated between twopins 6 u on the bar a. \Vhen the toothed wheel a has completed itsforward motion, as described, the pin a on bar it comes in contact withspring 5, and thereby throws the pawl 9 into engagement with the teethof the wheel, while on the backward motion of the arm f and pallet t'the pin 25 throws bar it out of engagement as soon as the pallet 2'comes into engagement with the teeth. The arm f is here shown actuatedin the forward direction by an electromagnet n, which is excited by acurrent at stated intervals of time, so as to attract an armature w onthe axis of the armf, the return motion being effected by an adjustableweight 3 on an arm projecting from arm f.

Although I have in all cases shown the arm f, to which the to-and-fromotion is imparted, pivoted to the casing at the lower end, yet it canalso be supported at its upper end and the electromagnet or other deviceforimparting motion thereto be applied ata point above the pallet-bar,as indicated at Fig. 6, Where the arm f has atits upper end a dovetailblock 1, which slides freely in a dovetail guide 2, fixed to the casingg, and is actuated in one direction by the electromagnet o and in theother direction by a spring 3. The arm is connected to and actuates thepallet-bar b and pallet-pins t' j in precisely the same manner asdescribed with reference to Figs. 1 and 2.

a is, as before, the toothed wheel, and Z is the ratchet-pawl.

My above-described invention is applicable with particular advantage toelectric clocks; but it may also be used with advantage in all mechanismin which an accurately-controlledstep-by-step rotary motion is requiredthat is effectually locked when each forward motion is completed.

Having thus described the nature of this invention and the best means Iknow of carrying the same into practical effect, I claim- 1. Inapparatus for effecting a step-by-step rotary motion, the combinationwith a toothed wheel to which a step-by-step rotary motion is to beimparted, of an arm receiving a toand-fro motion from any suitable powerand two pallets actuated by such arm so as to be alternately engagedwith opposite sides of said wheel so that the one pallet which only hasa to-and-fro motion radially of the said wheel comes into engagementtherewith before the other pallet which receives both a radialto-and-fro motion and a circumferential motion is brought out ofengagement,substantially as described.

2. In apparatus for effecting a step-by-step rotary motion, thecombination of a toothed wheel to which said rotary motion is to beimparted, means for rotating said wheel through a certain distance, apallet having a to-andfro motion radially of said Wheel only, andadapted to engage therewith when its partial rotation is completed, asecond pallet having both a radial and a circular motion adapted toengage with the opposite side of the wheel before it commences itspartial rotation, and a fixed stop with which the said second palletcomes in contact when the wheel has completed its motion, and means forimparting the radial motion to the two pallets so that the one alwayscomes into engagement with the wheel before the other passes out ofengagement, substantially asdescribed.

3. In apparatus for effecting a step-by-step rotary motion, thecombination of a toothed wheel a to which rotary motion is to beimparted, a bar I) having pallets t andj adapted to slide in and out ofengagement with the teeth of the wheel, fixed pins 0 0 between which theone end of bar Z) can slide only in aradialdirection, pins (1, (Zbetween which the other end of the bar can slide in a radial directionand also turn to a limited extent with the wheel, an arm f connected tothe bar l) and reoeivingato-and-fro motion by any suitmy hand inpresence of two subscribing Witable means, and an incline 70 on the barI) nesses. which in sliding against the one fixed pin d, t causes thebar to shift upwardly so as to effect JAMES JOHN S1 OOKALL SENR' 5 therotation of the Wheel a until arrested by Witnesses:

the second pin d, substantially as described. CHAS. D. ABEL,

In testimony whereof I have hereunto set- A. J. llIAXXVELL.

